It picked up 37 million extra subscribers in 2020, but just 18 million last year.
Netflix shares fell by 20% last night - their worst day on the stock market since July 2012 following lower than expected subscriber numbers.
The streaming service has added 8.3 million new customers in the last three months of 2021 - just short of target.
It picked up 37 million extra subscribers in 2020, but just 18 million last year.
Business journalist Gavin McLoughlin says it's the forecasts for the next quarter that's worrying investors: